Microsoft Outlook Outage Spreads Worldwide as Recovery Efforts Falter

Microsoft is struggling to restore its Outlook and Microsoft 365 services following a major global outage that left thousands of users unable to access their emails and disrupted several other business applications on Thursday, 12 November 2026. The disruption affected users across multiple regions, including the Americas, Europe and Asia. 

Microsoft initially blamed unusually high demand on its infrastructure, but later confirmed that servers had unexpectedly become unavailable, placing additional pressure on those still operating. By Friday morning, the company had acknowledged that its attempts to restore service weren't working as expected. 

While some users were beginning to regain access, Microsoft was still investigating why affected servers continued to stop responding.

Microsoft Confirms Recovery Efforts Aren't Working as Expected

Microsoft first acknowledged problems with Exchange Online, the cloud-based email service behind Outlook, on Thursday. Users reported being unable to open their inboxes, send emails or connect to their accounts through several different methods. According to Microsoft's official incident updates, the company initially identified elevated demand on infrastructure across multiple regions. 

It began moving traffic away from affected servers and restarting systems to restore capacity. However, those efforts didn't deliver the improvements Microsoft had expected. Some servers returned to normal operation after being restarted, only to become unresponsive again when they began receiving traffic. 

Microsoft subsequently reported that the additional load wasn't caused by an overall increase in users or requests. Instead, a large number of servers had unexpectedly become unavailable, leaving the remaining infrastructure to handle more traffic than normal. The company paused software deployments and configuration changes while investigating the disruption. 

It also began testing alternative recovery methods, including rebuilding affected servers using an earlier software configuration and temporarily limiting certain types of traffic. By early Friday, Microsoft said its investigation had identified a process responsible for establishing secure connections that was becoming overwhelmed. 

This was causing affected servers to stop processing requests. Engineers were preparing a configuration fix and reversing a recent network change that appeared to coincide with the outage. Microsoft hadn't confirmed whether that change was responsible for the disruption.

Outlook Outage Affects Users Across 74 Countries

The disruption quickly spread beyond the Americas, where Microsoft had initially reported connectivity problems. Outage tracking service Downdetector received reports from 74 countries and territories within approximately an hour, according to international coverage of the incident. 

In the United States, Outlook problem reports peaked at 138,058 at around 1pm Eastern Time on Thursday, according to Reuters' reporting on the disruption. By the evening, that figure had fallen to approximately 34,490, although the company was still working to restore service. 

Downdetector's figures represent reports submitted through its monitoring system rather than the total number of affected users. Microsoft hasn't confirmed how many people or organisations were impacted worldwide. The outage also disrupted access to Exchange Online through Outlook on the web, desktop applications, mobile connections and other services that rely on Microsoft's email infrastructure. 

Some users experienced delayed email delivery, while others couldn't connect to their mailboxes at all. The problems continued into Friday in parts of Asia, where businesses were beginning their working day.

Teams, Copilot and Security Services Also Affected

Although Outlook was at the centre of the disruption, the problems extended across Microsoft's wider cloud services. Microsoft confirmed that features in Teams, SharePoint Online, Microsoft 365 Copilot and several security and administration tools were affected. 

However, the company said that functions which didn't depend on the affected Exchange Online services remained operational. For Teams users, the problems included calendar access and meeting scheduling. Core messaging and online meetings remained largely functional, according to Microsoft's service updates.

Microsoft 365 Copilot users could also experience problems loading chats, receiving responses or accessing work information stored in emails, calendars and files. The disruption extended to Microsoft Defender and Purview, affecting some security monitoring, data protection and compliance functions. Administrators also reported problems accessing parts of the Microsoft 365 admin centre. 

Other affected functions included Microsoft Graph requests involving email and calendar data, along with some operations in Planner, Intune and Power BI. The outage also affected services outside Microsoft's own product range. 

Reuters reported that OpenAI and Anthropic experienced problems with their Microsoft 365 connectors, which allow their AI tools to interact with Microsoft services. OpenAI reported problems establishing new connections, while Anthropic identified an issue with an upstream provider.

Microsoft Continues Work to Restore Services

Microsoft's recovery efforts were still underway in its early Friday incident updates, with engineers testing changes intended to prevent servers from becoming unresponsive when traffic returned. The company reported limited recovery in some regions after moving connections to alternative infrastructure. 

However, it continued investigating the underlying technical problem while gradually restoring traffic to affected systems. According to Associated Press' coverage of the outage, the disruption also affected some government operations, including Japan's shared government IT infrastructure. 

Microsoft has identified the incidents under reference numbers EX1550543 for Exchange Online and MO1550821 for the wider Microsoft 365 disruption. The company hasn't yet confirmed a definitive root cause or a complete restoration of all affected services in the latest incident information verified for this report. 

Organisations can check the Microsoft 365 admin centre's Service Health dashboard for updates affecting their services.